Cutter-support for hollow-mandrel lathes



Nrrn *rari-3s A'rnivr irren..

ELISHA H. HUDSON, OF POTTERSVILLE, MICHIGAN.

QPECIFICATION forming part of Letters Patent No. 305,519, datedSeptember 23, 1884.

Application led September 6, 1883.

Rene-wed July 21, 1884. (No model.)

.To f1/ZZ whom it may concern.-

Be it known that I, Emsnn` H. HUDsoN, of

\ Pottersville,in the State-of Michigan, have invented certain new anduseful Improvements in Gutter-Supports for Hollow-Mandrel Lathes; and Ido hereby declare that the following is a full, clear, and exactdescription thereof,

' 1 reference being had to the accompanying drawings, and to the lettersof reference marked hereon, which form a part of this specificarlhisinvention relates to devices for supporting the cutters in the class oflathes in which a hollow mandrel is employed for carrying the cutters,through which mandrel the p article passes inthe act of being turned.Its

object is to provide an improved construction in the devices mentioned;and it consists in the matters hereinafter described,and pointed out inthe claims.

The invention is illustrated in theaecompanying drawings in connectionwith the hollow mandrel of a lathe having movable cutters and Wedges forcontrolling the same, such as .upon line .00 m of Fig. 1.

is shown and described in an application for Letters Patent of theUnited States made by me on the 24th day of November, 1882.

In the accompanying drawings, Figure l is .a side elevation of ahollowlathe mandrel with my improved cutter-support attached. Fig. 2 is alongitudinal section through the axis of the` mandrel, taken upon` linea: x of Fig. 3. Fig. 3 is a transverse section taken Fig.`4c is atransverse section of the mandrel upon the line c y of Fig. l, showingthe cutter supporting arms in side view. Fig. 5 is a detail lsectionupon -line y y of Fig. 3.

A is a hollow rotating mandrel, which, as shown, is mounted in bearingsa, and is provided with a driving-pulley, A', and a cuttersupporting armstrueture,B,having two arms, B', which carry finishing-cutters C C'. The

mandrel illustrated is intended to operate in connection with suitabledevices for moving the cutters, so as to vary the form of the articlebeing turned, such as are shown and described, for instance, in theapplication above referred to, and is provided with a cutterhead, A2, inwhich are mounted shaping-cutin which the finishing-cutters C G' areinsert' ed. The said cutters are preferably curved or bent transverselynear their cutting-edges, and are arranged tangentially with referenceto the orifice or bore of the mandrel and eX- tended outwardly in longspring-steel Shanks, the ends of which are clamped `in the extremitiesof the said supporting-arms B. The inner or cutting ends of the kniveswhich enter the apertures a' in the mandrel, as before stated, are adjustabl y supported and controlled by wedges D, which are arrangedlongitudinally against the outer surface of the mandrel,

and are supported in seatsin the arms B', said wedges beinglongitudinally movable,so as to raise and lower the knives, and tothereby vary the diameter of the article being turned, as fully setforth in the application above referred to. The ends of the wedges Dproject at one side of the arms B', and are connected to a sliding ring,E, which is placed around` the mandrel A,and which maybe -actuated bythe devices set forth in the above-mentioned application, or by anyother well known or preferred devices for the saine purpose;

As an improved construction in the knifecarrying arm structure B, forsupporting the knives, such structure is made lin two parts', B', ofsimilar form, each of `said parts having -a semicircular portion, B3,which is placed around the mandrel, and a straight portion, B, thelatter forming one of the cutter-supporting arms proper. Thesemicircular portion B of the parts B' are curved upon their inner facesto t the exterior of the mandrel, so that by placing the saidsemicircular portions of the parts B' opposite each other upon themandrel, they will meet at opposite sides thereof and encircle'it. Theparts B are at- 'tached to the mandrel by securing them together at thepoints at which the semicircular parts B3 meet when placed around it, soas to clamp such parts firmly thereon, the arms B2 being arranged toproject in opposite directions, as shown. As preferably constructed,

each part B has upon the end of its semicircular portion one or moretransversely-projecting threaded continuations, b, constructed to passthrough corresponding apertures, b3, 1n

the opposite part, the two parts being securedv gentially with referenceto the bore of the mandrel, as before stated, are secured to the arms Bby having the outer endsof their shanks c and o secured between thecross-bar b5, joining the extremities of said arms, and a clamping-bar,Bt, secured at its ends to the ends of the arms by means of bolts b, asshown.

The wedges D, which are located beneath the cutters C and C and inlcontact with the mandrel, are fitted into and supported at their rearedges and outer faces by seats formed in each ot' the two part-s Bcomposing the arm structure, preferably at or near the points ofjuncture of the semicircular portions B3 thereof, as shown, and aspreferably constructed the wedge-seats are formed partially in each ofthe two parts B', as more plainly shown at b8 and b. in Fig. 4. rlheportions bs of the wedgeseats, against which the rear edges of thewedges bear, are preferably located at the points of the intersection ofthe semicircular parts B3 with the arms B2, and are formed in thecross-pieces bl, which join the two sides of the arm structure at suchpoints, as shown clearly in Figs. 3 and 5. By this constructioncontinuous bearing-surfaces are formed for the rear'edges of the wedges,and such surfaces are protected from dust and shavings. The portions biof the wedge-seats are in the form of notches in the ends ofthesemicircular parts B3, such projections forming extensions of thebearing surfaces of the outer faces ofthe wedges at the ends thereof,and being extended circumferentially around the mandrel, so as to permitthe requisite amount of the movement in the wedges, as shown moreclearly in Fig. 4. The cross-pieces if are for the purpose of givingrigidity to the portions B3 of the arm structure, and are preferablylocated upon the mandrel between the oppositely-arran ged cutterapertures c. The said apertures a', as shown, are extended beneath thewedges D,

and communicate with the space between the cross-pieces b and bl, so asto permit the escape of shavings from beneath the cutters, as

shown and described in the application forl patent before referred to. Y

As an improved construction in the finishing'cutters C and C', one ofsaid cutters, C, is constructed to cut at a slightly less depth than theother cutter, and the portion`thereof that is nearest the entrance endof the mandrel is curved outwardly, as shown clearly in Figs. 1 and 3,such ou twardly-turned portion' being in advance of any portion of theopposite cutter, so as to remove the principal part of the materialwhich is cut away in making the tapered or other form to the blank. Theopposite cutter,-C, .is so located that the central portion of itscurved cutting-edge is slightly at the rear of or nearer the exit end ofthe mandrel'than the corresponding portion of the cutter C, so that inthe forward movement of the blank in passing through the spindle suchcutter- C follows the cutter first mentioned and operates to nallyfinish the surface ofthe wood. The cutter C is constructed to cut veryslightly deeper than the cutter C, so as to remove a very thin shaving,so that its wdrk is limited to the operation of smoothing the article.By this construction in the cutter C very little strain comes upon itduring its operation, and s its cutting-edge is therefore not liable tobe worn out rapidly, and may be retained in a more perfect condition foriinishing than ifit were constructedl to remove a considerable quantityof material from the blank. VAnother advantage arising from theconstruction last described is that the edge of the finishing-cut ter Omay be advanced to a point opposite the center of the blank, or so thatit is located tangentially with reference to the cylindrical' surfacethereof, so that it will operate to shave the wood more smoothly thanlwhen set at an angle therewith, and when in such position will have notendency to ridel up or leave the work, as is liable to be the case whena cutter so placed is constructed to cut to a considerable depth.

rlhe cutter C, in order to cause it to bite into the wood, is usuallylocated with its cutting edge at an angle to the surface of the blank,and has therefore no tendency to leave the work. f

By constructing the cutter-supporting arms in two similar parts, asabove set forth, such arms can be much more readily manufactured andapplied than as heretofore constructed.

The fact that the parts are exactly alike lessthe arm structure beingreadily accessible for IOO IIO

the purpose of planing them out or otherwise nishing them.

I claim as my invention---`` other part, and nuts b2 upon saidprojections for clamping the parts upon the mandrel, sub` stantially asdescribed.

3. The combination, with a hollow lathemandrel, of a cutter-supportingarml structure consisting of two parts, B',having semicircular portionsB3, constructed to embrace the mandrel, and provided with wedge seatsformed in said semicircular portions, and means for securing said partstogether, substantially as described.y

4. The combination, with a hollow lathemandrel, movable cutters, andwedges for moving the cutters, of a cutter supporting arm structureconsisting of two parts, B', each having semicircular portions B3, andconsisting of two laterally-separated and parallel arms, and cross-bars1)?,ccnneeting the said arms, and having wedge-seats b8 formed therein,substantially as described.

5. The combination, with a hollow lathe- -mandrel provided withroughing-cutters constructed to reduce the blank to the size of themandrel-bore and movable wedges, of movable finishing-cutters lC and C',supported upon said mandrel, one of said cutters, C, being provided witha flared cutting-edge, c?, in advance of the other cutter, C', and thesaid cutter C' being constructed to cut slightly deeper than the cutterC, substantially as described.

In testimony that I claim the foregoing as my invention I afx mysignature in presence of two witnesses.

ELrsHA H. HUDSON.

Vitnesses:

M. E. DAYTON, Jnssn COX, J r.

